Solvent Extraction

Solvent extraction, also called liquid-liquid extraction, is a chemical separation method that exploits a compound's differing solubility in two immiscible liquids, typically water and an organic solvent, to transfer a desired substance out of one liquid phase and into the other so it can be isolated or purified. On a laboratory scale the technique is carried out in a separatory funnel, while industrial operations use equipment such as mixer-settlers, pulsed columns, and centrifugal extractors to maximize contact between the two liquid phases; the PUREX process, which separates uranium and plutonium during nuclear fuel reprocessing, is a major industrial-scale application. Solvent extraction using chelating agents is also widely used to separate and purify metal ions, and the method is central to pharmaceutical manufacturing and the production of fragrances and flavorings. No single clean origin date or inventor for the general technique is established in the source consulted; it developed gradually as an extension of ordinary chemical separation practice.